Some 15.5 percent of women in the United States may be at higher risk for developing breast cancer as a result of their genetic inheritance and factors relating to their personal history (Freedman, 2003). Intensified screening and chemoprophylaxis are among the monitoring and prevention options available to these women. The decision to begin tamoxifen therapy, in particular, is a complex and difficult one. While the protective effects of this selective estrogen replacement modulator have been well-established, side effects such as hot flashes and collateral risks for developing blood clots and uterine cancer subsequent to therapy are countervailing considerations. The United States Preventive Services Task Force has recently recommended that Primary Care physicians provide counseling regarding the tamoxifen option to their high risk women patients, and other physicians in Breast Health Programs and in Women's Health Centers have been providing these services to their patients for a decade or more (Kinsinger, 2002). A prototype Internet-based multimedia education program focusing on breast cancer issues and tamoxifen prophylaxis will be developed for high-risk Caucasian and African-American women. The program will include images, text, graphics, and video teaching content, along with an individualized risk assessment and an interactive decision planning module. The educational intervention is intended to complement personal counseling on breast health by a physician. Printed feedback regarding level of risk and decision factors will be provided to the woman patient and to her physician. An annotated checklist of discussion topics will be provided to structure the counseling session. Social learning theory, self-efficacy theory, and social marketing principles will be employed in the design of the health education program. Both short-term and intermediate-term outcomes will be measured. Knowledge of breast cancer topics, pros and cons of tamoxifen, attitudinal and behavioral variables, satisfaction with the tamoxifen decision, and satisfaction with the decision process will be assessed. Pre-Post data will be collected online and a Follow-Up survey will be conducted one month later by email and telephone. Physician ratings of their patient's understanding of relevant issues will be appended to the data record. Qualitative data will be collected to assist in the design of a Phase II clinical trial comparing web, counseling, and print education modalities.